ŠTEFUŠOVÁ, K. ., LOVÁS, M. ., ZUBRIK, A. ., MATIK, M. . and VÁCLAVÍKOVÁ, M. . (2012) “Removal of Cd2+ And Pb2+ from Aqueous Solutions Using Bio-Char Residues”, Nova Biotechnologica et Chimica, 11(2), pp. 139–146. doi: 10.2478/v10296-012-0016-x.